From: Alexander Tsoy <alexander@tsoy.me>
To: Pavel Hofman <pavel.hofman@ivitera.com>,
"alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>
Subject: Re: High-bandwidth/multiple transactions per microframe in usb audio?
Date: Sat, 25 Apr 2020 22:50:03 +0300 [thread overview]
Message-ID: <253259a4ef8a2bcfa0568982b8fd23d5e2d0937a.camel@tsoy.me> (raw)
In-Reply-To: <3a44ca23-f0ed-af54-3e63-8bf77d833c8f@ivitera.com>
В Сб, 25/04/2020 в 20:06 +0200, Pavel Hofman пишет:
> Dne 25. 04. 20 v 14:06 Alexander Tsoy napsal(a):
> > В Пт, 24/04/2020 в 11:42 +0200, Pavel Hofman пишет:
> > > Hi,
> > >
> > > Please does the current USB audio driver support multiple
> > > transactions
> > > per microframe (high-bandwidth mode)? I could not find it in
> > > endpoint.c
> > > but it may be there or somewhere else :-)
> >
> > This should be transparent for the driver. See usb_submit_urb()
> > function from drivers/usb/core/urb.c. It allows packets larger than
> > 1024 for isochronous transfers over High Speed and Super Speed
> > buses.
>
> Alexander, thanks a lot for the info and hint, indeed at
> https://github.com/torvalds/linux/blob/master/drivers/usb/core/urb.c#L444
>
And I just noticed that USB-audio driver can't properly parse max
packet size for SuperSpeed and SuperSpeed+ devices yet. See
audio_format_alloc_init().
next prev parent reply other threads:[~2020-04-25 19:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-24 9:42 High-bandwidth/multiple transactions per microframe in usb audio? Pavel Hofman
2020-04-25 12:06 ` Alexander Tsoy
2020-04-25 18:06 ` Pavel Hofman
2020-04-25 19:50 ` Alexander Tsoy [this message]
2020-04-26 8:55 ` Pavel Hofman
2020-04-27 14:05 ` Takashi Iwai
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